A woman is suing the head of Japan's biggest yakuza organised crime group over protection money she paid to gangsters.

She claims the don of the Yamaguchi-gumi, Kenichi Shinoda, bears "employer’s liability" for the gangsters who threatened to burn down her bar if she did not pay up.

The woman, who has not been named, is demanding Shinoda hands over 17m yen (£112,000) after mobsters forced her to pay between 30,000 and 100,000 yen a month between 1998 and 2010.

Image Caption:Shinoda on his release from prison in 2011

She says Shinoda bears ultimate responsibility for her losses because the gangsters, members of the Inabaji Ikka, a local yakuza group connected to Yamaguchi-gumi, were affiliated to his nationwide umbrella crime syndicate.

On one occasion in 2008 when she tried to refuse to pay, she was warned that her bar in the central city of Nagoya could be burned down.

Lawyers say it is the first case of someone demanding recompense for protection money from a senior yakuza figure.

It comes as the owner of another bar begins legal action against Shinoda, claiming affiliated criminals burned down his business after he refused to pay protection money.

The Yamaguchi-gumi makes up more than 40% of the nation's organised criminals, with about 27,700 members, according to the National Police Agency.

Like the Italian mafia or Chinese triads, the yakuza engages in activities ranging from gambling, drugs and prostitution to loan sharking, protection rackets and white-collar crime.

The gangs, which are not illegal, have historically been tolerated by the authorities, although there are periodic clampdowns on some of their less savoury activities.

The yakuza are heavily mythologised in Japan, with films, television dramas and fan magazines glamorising lives of violence governed by a code of honour handed down from the samurai.